Threshold SL10, Nelson Pass vintage preamplifier with separate power supply
Active Circuit Data:
performance of basic gain stages. (measured to IHF standards A202 for distortion specifications).
preliminary phono gain stage:
(all measurements made at highest input impedance) FREQUENCY RESPONSE: .3 Hz through 500,000 Hz, +0, -3dB.
SQUARE WAVE RISE TIME: .5 microseconds.
TOTAL HARMONIC DISTORTION: .015% second harmonic @ 50 millivolts out .. 03% second harmonic @ 100 millivolts out, NOISE: (preliminary phono gain stage + RIAA gain stage): -80dB A weighted referenced to 1 volt out. - 72dB unweighted referenced to 1 volt out.
CROSSTALK: (left minus right) > -7OdB @ 1,000 Hz.
INPUT OVERLOAD: 70 millivolts peak for any frequency. INPUT IMPEDANCE: selectable 1 through 15 ohms, 15 through 30 ohms, 30 through 50 ohms.
RIAA phono gain stage:
RIAA EQUALIZATION: no greater than .5dB deviation at frequency extremes.
TOTAL HARMONIC DISTORTION: 012%. 20Hz through 20,000 Hz @ 2 volts out. typically: .008% @ 1.000 Hz.
SMPTE INTERMODULATION DISTORTION: .006% @ 1 volt out.
NOISE: -90dB A weighted referenced to 1 volt out. -75 dB unweighted referenced to 1ยท volt out.
CROSSTALK: (left minus right) -70 dB @ 1.000 Hz.
INPUT IMPEDANCE: 47.000 ohm and selectable 100 pI, 200 pf. or 400 pf.
INPUT OVERLOAD: 320 millivolt peak @ 1.000 Hz. OUTPUT IMPEDANCE (tape out): 1,000 ohms. GAIN FACTOR: +33dB @ 1,000 Hz.
High Level Gain Stage:
(performance of the basic gain stage outside the system) FREQUENCY RESPONSE: dc through 500,000 Hz. +0. -3dB. SQUARE WAVE RISE TIME: <.6 microseconds. PROPAGATION DELAY: input to output transit time: <.02 microseconds.
PHASE SHIFT: <10 degrees at 1,000,000 Hz. SLEW RATE: 150 volts/microsecond.
TOTAL HARMONIC DISTORTION: .003%, 20 Hz through 5,000 Hz .. 006%, 5,000 Hz through 20,000 Hz @ 5 volts out into 10,000 ohm, 1,000 pf load.
SMPTE INTERMODULATION DISTORTION: .008%, 10.000 Hz @ 5 volts out into 10,000 ohm, 1,000 pf load.
CROSSTALK: left channel to right channel; -6OdB @ 1,000 Hz. tuner to auxiliary; -65dB @ 1,000 Hz.
GAIN FACTOR: +2OdB.
MAXIMUM OUTPUT BEFORE CLIPPING: ::12 volts peak.
Dimensions:
Faceplate: 19 inches wide, 2.62 inches high.
Chassis: 17 inches wide, 2.215 inches high, 8 inches deep. Power supply: 8 inches wide. 3.375 inches high, 5 inches deep.
